Flexible PDMS-NdFeB Composite Membrane for Haptic Force Perception

With the continuous development of virtual reality and augmented reality, haptic actuators have become a focused research area to provide richer interactive behavior, following the development of visual and auditory displays. Flexible materials are more conducive to wearable devices compared to traditional rigid haptic actuators with their small form factor and superior skin conformity. These characteristics hold promise for providing humans with a more diverse range of tactile force sensations and textural experiences. This paper presents a 500 μm-thick flexible PDMS-NdFeB composite magnetic film for tactile force feedback devices. The magnetic films, with different NdFeB contents and various surface textures, are fabricated by 3D printing mold casting. After being magnetized, these films can generate different magnetic flux density ranges from 8 to 25 mT due to different component contents of PDMS and NdFeB. A magnetic force of approximately 20 mN can be obtained by wearing the present flexible film under 25 mT, which is consistent with the simulation data and can be well-perceived by human fingertips. Additionally, flexible magnetic films with various surface textures were designed; in a cognitive experiment, the textured surfaces of the fabricated magnetic films could be almost perfectly identified. This work provides a solution for haptic interaction, which can also promote the wearable and miniaturization of tactile devices.